TY - JOUR

T1 - Organic carbon accumulation in British saltmarshes

AU - Smeaton, Craig

AU - Garrett, Ed

AU - Koot, Martha B

AU - Ladd, Cai J T

AU - Miller, Lucy C

AU - McMahon, Lucy

AU - Foster, Bradley

AU - Barlow, Natasha L M

AU - Blake, William

AU - Gehrels, W Roland

AU - Skov, Martin W

AU - Austin, William E N

N1 - Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.

PY - 2024/5/20

Y1 - 2024/5/20

N2 - Saltmarshes are a crucial component of the coastal carbon (C) system and provide a natural climate regulation service through the accumulation and long-term storage of organic carbon (OC) in their soils. These coastal ecosystems are under growing pressure from a changing climate and increasing anthropogenic disturbance. To manage and protect these ecosystems for C and to allow their inclusion in emissions and natural-capital accounting, as well as carbon markets, accurate and reliable estimates of OC accumulation are required. However, globally, such data are rare or of varying quality. Here, we quantify sedimentation rates and OC densities for 21 saltmarshes in Great Britain (GB). We estimate that, on average, saltmarshes accumulate OC at a rate of 110.88 ± 43.12 g C m yr . This is considerably less than widely applied global saltmarsh averages. It is therefore highly likely that the contribution of northern European saltmarshes to global saltmarsh OC accumulation has been significantly overestimated. Taking account of the climatic, geomorphological, oceanographic, and ecological characteristics of all GB saltmarshes and the areal extent of different saltmarsh zones, we estimate that the 451.65 km of GB saltmarsh accumulates 46,563 ± 4353 t of OC annually. These low OC accumulation rates underline the importance of the 5.20 ± 0.65 million tonnes of OC already stored in these vulnerable coastal ecosystems. Going forward the protection and preservation of the existing stores of OC in GB saltmarshes must be a priority for the UK as this will provide climate benefits through avoided emissions several times more significant than the annual accumulation of OC in these ecosystems. [Abstract copyright: Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.]

AB - Saltmarshes are a crucial component of the coastal carbon (C) system and provide a natural climate regulation service through the accumulation and long-term storage of organic carbon (OC) in their soils. These coastal ecosystems are under growing pressure from a changing climate and increasing anthropogenic disturbance. To manage and protect these ecosystems for C and to allow their inclusion in emissions and natural-capital accounting, as well as carbon markets, accurate and reliable estimates of OC accumulation are required. However, globally, such data are rare or of varying quality. Here, we quantify sedimentation rates and OC densities for 21 saltmarshes in Great Britain (GB). We estimate that, on average, saltmarshes accumulate OC at a rate of 110.88 ± 43.12 g C m yr . This is considerably less than widely applied global saltmarsh averages. It is therefore highly likely that the contribution of northern European saltmarshes to global saltmarsh OC accumulation has been significantly overestimated. Taking account of the climatic, geomorphological, oceanographic, and ecological characteristics of all GB saltmarshes and the areal extent of different saltmarsh zones, we estimate that the 451.65 km of GB saltmarsh accumulates 46,563 ± 4353 t of OC annually. These low OC accumulation rates underline the importance of the 5.20 ± 0.65 million tonnes of OC already stored in these vulnerable coastal ecosystems. Going forward the protection and preservation of the existing stores of OC in GB saltmarshes must be a priority for the UK as this will provide climate benefits through avoided emissions several times more significant than the annual accumulation of OC in these ecosystems. [Abstract copyright: Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.]

KW - Blue carbon

KW - Climate

KW - Coastal

KW - Nature-based solutions

KW - Radionuclide

KW - Wetlands

U2 - 10.1016/j.scitotenv.2024.172104

DO - 10.1016/j.scitotenv.2024.172104

M3 - Article

C2 - 38556016

VL - 926

SP - 172104

JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 0048-9697

ER -